PCB circuit board with character printing detection mechanism

Abstract

This utility model discloses a PCB circuit board with a text printing inspection mechanism. The board body consists of a substrate, a copper foil layer, and a solder mask layer. The copper foil layer covers the top of the substrate, and at least two reference alignment copper pads are provided on the top of the copper foil layer. The solder mask layer covers the top of the copper foil layer and the reference alignment copper pads. A text silkscreen layer is also provided on the top of the solder mask layer, and a character circle matching the position of the reference alignment copper pad is formed on the text silkscreen layer. Compared with the prior art, in this utility model, when the reference alignment copper pad is located within the character circle of the text silkscreen layer, the text silkscreen position is accurate. When there is a deviation in the position of the reference alignment copper pad relative to the character circle, the text silkscreen position also deviates. Therefore, personnel can judge whether there is a deviation in the silkscreen text by observing the relative position of the reference alignment copper pad and the character circle, thereby promptly rejecting PCB boards with unqualified text printing for rework.

Description

Technical Field

[0001] This utility model relates to the field of PCB board technology, and in particular to a PCB board with a text printing detection mechanism. Background Technology

[0002] In the manufacturing process of printed circuit boards (PCBs), text printing (silk screen printing) is a key process for identifying component reference numbers, polarity, and manufacturer information, which directly affects subsequent assembly efficiency and product traceability.

[0003] However, due to the complexity of the circuit board manufacturing process and the inherent characteristics of the materials, the text printing process has long faced a variety of problems that result in poor screen printing effects. For example, the screen printing stencil is prone to deformation due to mechanical stress and environmental temperature and humidity, which causes the ink transfer position to shift. In addition, traditional positioning pins cannot effectively suppress the micro-displacement of the PCB on the screen printing machine due to mechanical wear, insufficient tolerance matching and equipment vibration, which exacerbates the risk of text and image misalignment.

[0004] However, text misalignment defects on printed circuit boards (such as incomplete characters or blurred engravings) do not have obvious characteristics immediately after screen printing, making it difficult for staff to detect the defects in time. They are usually only discovered during the final inspection stage, by which time the entire board is almost finished, and the cost of rework is high. Utility Model Content

[0005] The main purpose of this invention is to provide a PCB circuit board with a text printing detection mechanism. When the reference alignment copper pad is located within the character circle of the text silkscreen layer, the text silkscreen position is accurate. When the position of the reference alignment copper pad relative to the character circle is deviated, the text silkscreen position is also deviated. Therefore, personnel can judge whether there is a deviation in the silkscreen text by observing the relative position of the reference alignment copper pad and the character circle, so as to promptly remove PCB boards with unqualified text printing and rework them.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A PCB circuit board with a text printing inspection mechanism, the board body is composed of a substrate, a copper foil layer and a solder mask layer, the copper foil layer covers the top of the substrate, at least two reference alignment copper pads are provided on the top of the copper foil layer, the solder mask layer covers the top of the copper foil layer and the reference alignment copper pads, and a text silkscreen layer is also provided on the top of the solder mask layer, the text silkscreen layer has character circles that match the positions of the reference alignment copper pads.

[0007] Furthermore, the reference alignment copper pad is a protrusion, and the protrusion is integrally formed with the copper foil layer.

[0008] Furthermore, in the direction perpendicular to the plate, the reference alignment copper pad and the corresponding solder mask area on its top are completely located within the internal space defined by the character circle.

[0009] Furthermore, the cross-section of the reference alignment copper pad and the character ring is circular.

[0010] Furthermore, the diameter of the character ring is 5-8 mil larger than the diameter of the reference alignment copper pad.

[0011] Furthermore, at least two limiting holes are provided on the plate.

[0012] Compared with the prior art, the present invention has the following beneficial effects: When the reference alignment copper pad of this invention is located within the character circle of the text silkscreen layer, the text silkscreen position is accurate. However, if there is a deviation in the position of the reference alignment copper pad relative to the character circle, the text silkscreen position will also be deviated. Therefore, personnel can judge whether there is a deviation in the silkscreen text by observing the relative position of the reference alignment copper pad and the character circle, so as to promptly remove PCB boards with unqualified text printing and rework them.

[0013] In this invention, the reference alignment copper pad and its top solder mask are both located inside the character ring. Therefore, the solder mask on the top of the reference alignment copper pad will not extend beyond the character ring, thus preventing the solder mask on the top of the reference alignment copper pad from being worn down due to contact with other structures. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a PCB circuit board with a text printing detection mechanism according to the present invention.

[0015] Figure 2 This is a schematic diagram of the board structure of a PCB circuit board with a text printing detection mechanism according to the present invention.

[0016] Figure 3 This is a schematic diagram showing the connection between the reference alignment copper pad and the character ring of a PCB circuit board with a text printing detection mechanism according to this utility model.

[0017] In the diagram: 1. Board body; 101. Substrate; 102. Copper foil layer; 103. Solder mask layer; 1031. Reference alignment copper pad; 104. Text silkscreen layer; 1041. Character ring; 2. Limiting hole. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0019] like Figure 1-3As shown, a PCB circuit board with a text printing inspection mechanism includes a board body 1. The board body 1 is composed of a substrate 101, a copper foil layer 102, and a solder mask layer 103. The copper foil layer 102 covers the top of the substrate 101. At least two reference alignment copper pads 1031 are provided on the top of the copper foil layer 102. The solder mask layer 103 covers the top of the copper foil layer 102 and the reference alignment copper pads 1031. A text silkscreen layer 104 is also provided on the top of the solder mask layer 103. Character circles 1041 that match the positions of the reference alignment copper pads 1031 are formed on the text silkscreen layer 104.

[0020] The substrate 101, copper foil layer 102 and solder resist layer 103 are components of the PCB circuit board, which is prior art and will not be described in detail here. The text silkscreen layer 104 is printed by a silkscreen machine, which is also prior art and will not be described in detail here.

[0021] In this embodiment, such as Figure 1 As shown, limit holes 2 are provided at all four corners of the board body 1. Then, positioning pins are used to fix the board body 1 to the screen printing machine through the limit holes 2. When screen printing, if the text position is accurate, the reference alignment copper pad 1031 will be located within the character circle 1041 of the text screen printing layer 104. If the text position is deviated, the reference alignment copper pad 1031 will be deviated from the character circle 1041 of the text screen printing layer 104. Therefore, personnel can judge whether there is a deviation in the text of the screen printing by observing the relative position of the reference alignment copper pad 1031 and the character circle 1041, so as to promptly remove PCB boards with unqualified text printing.

[0022] Once the PCB board is fully formed, it will be milled away according to the alignment copper pad 1031.

[0023] Among them, such as Figure 2 and Figure 3 As shown, the reference alignment copper pad 1031 is a protrusion, which is integrally formed with the copper foil layer 103. When the solder mask layer 103 is sprayed with ink, corresponding holes will be reserved on the screen. The holes correspond to the positions of the reference alignment copper pad 1031. When the ink enters the hole, it will be confined by the hole. After curing, it will cover the top of the reference alignment copper pad 1031. Furthermore, the reference alignment copper pad 1031 and the solder mask layer 103 on top of it are both located inside the character ring 1041. Therefore, the solder mask layer 103 on top of the reference alignment copper pad 1031 will not protrude from the character ring 1041, thus avoiding wear due to contact with other structures. This makes it easier for personnel to observe whether there is any displacement of the position of the reference alignment copper pad 1031 relative to the character ring 1041.

[0024] Among them, such as Figure 2As shown, the cross-sections of the reference alignment copper pad 1031 and the character ring 1041 are circular. The diameter of the character ring 1041 is 5-8 mil larger than the diameter of the reference alignment copper pad 1031, so as to ensure that personnel can visually judge whether there is an offset between the reference alignment copper pad 1031 and the character ring 1041.

[0025] The working principle is as follows: When applying the solder mask layer 103, holes are pre-drilled on the screen, corresponding to the positions of the reference alignment copper pads 1031. When the ink enters these holes, it is confined by the holes and, after curing, covers the top of the reference alignment copper pads 1031. Then, when printing the text silkscreen layer 104, a masking layer matching the reference alignment copper pads 1031 is left on the text silkscreen. Therefore, after the text silkscreen layer 104 is printed, it forms a layer around the reference alignment copper pads 1031. If the text is positioned correctly, the reference alignment copper pad 1031 will be located within the character circle 1041 of the text silkscreen layer 104. However, if the text position is off, the reference alignment copper pad 1031 will be off relative to the character circle 1041 of the text silkscreen layer 104. Therefore, personnel can judge whether there is a deviation in the silkscreen text by observing the relative position of the reference alignment copper pad 1031 and the character circle 1041, so as to promptly remove PCB boards with unqualified text printing.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A PCB circuit board with a text printing detection mechanism, comprising a board body (1), characterized in that: The board (1) is composed of a substrate (101), a copper foil layer (102) and a solder mask layer (103). The copper foil layer (102) covers the top of the substrate (101). At least two reference alignment copper pads (1031) are provided on the top of the copper foil layer (102). The solder mask layer (103) covers the top of the copper foil layer (102) and the reference alignment copper pads (1031). A text silkscreen layer (104) is also provided on the top of the solder mask layer (103). A character circle (1041) matching the position of the reference alignment copper pads (1031) is opened on the text silkscreen layer (104).

2. The PCB circuit board with a text printing detection mechanism according to claim 1, characterized in that: The reference alignment copper pad (1031) is an upward protrusion, and the reference alignment copper pad (1031) is integrally formed with the copper foil layer (102).

3. The PCB circuit board with text printing detection mechanism according to claim 1, characterized in that: In the direction perpendicular to the plate (1), the reference alignment copper pad (1031) and the corresponding solder mask (103) area on its top are completely within the internal space defined by the character circle (1041).

4. The PCB circuit board with text printing detection mechanism according to claim 1, characterized in that: The cross-sections of the reference alignment copper pad (1031) and the character ring (1041) are circular.

5. The PCB circuit board having a text print detection mechanism according to claim 4, wherein: The diameter of the character ring (1041) is 5-8 mil larger than the diameter of the reference alignment copper pad (1031).

6. The PCB circuit board with text printing detection mechanism according to any one of claims 1-5, characterized in that: At least two limiting holes (2) are provided on the plate (1).

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